• bearophile <bearophileHUGS lycos.com> Oct 24 2009
• Yigal Chripun <yigal100 gmail.com> Oct 25 2009
• bearophile <bearophileHUGS lycos.com> Oct 26 2009

bearophile <bearophileHUGS lycos.com> writes:

Yigal Chripun:
 there should be no syntactic difference between an int and a user 
 defined type.
 for example I should be able to do:
 struct foo : int {}


With "alias this" D2 is able to do something like that, but it uses a
nonstandard syntax... So here things may be improved in D2.

Bye,
bearophile

Yigal Chripun <yigal100 gmail.com> writes:

On 25/10/2009 08:47, bearophile wrote:
 Yigal Chripun:
 there should be no syntactic difference between an int and a user
 defined type.
 for example I should be able to do:
 struct foo : int {}


 With "alias this" D2 is able to do something like that, but it uses a
nonstandard syntax... So here things may be improved in D2.

 Bye,
 bearophile


This is one aspect that D inherited from C which I really dislike. 
adding alias this to the mix is adding a sin to a crime (as the Hebrew 
saying goes).

Scala shows how this can be properly designed.

D has many (sometimes very powerful) hacks that could and should be 
replaced with a much better general solution.
for instance there's special handling of void return types so it would 
be easier to work with in generic code. instead of this compiler hack a 
much simpler solution is to have a unit type and ditch C style void. the 
bottom type should also exist mainly for completeness and for a few 
stdlib functions like abort() and exit()

bearophile <bearophileHUGS lycos.com> writes:

Yigal Chripun:

 D has many (sometimes very powerful) hacks that could and should be 
 replaced with a much better general solution.


Sometimes fully orthogonal designs aren't the best because they force the
programmer to do too much "assembly required". A good language has to offer
some handy pre-built/highlevel constructs for the most common operations, that
can save lot of work. Sometimes general solutions produce slow programs, or
they require a more complex/smarter/slower compiler (I need a new word there,
"complexer"? Natural languages too need updates now and then).
But I agree that in few parts D can enjoy a redesign. Andrei is doing some work
on this, and quite more work can be done. The "alias this" looks like a little
hack too me too. A safer or more "theoretically sound" solution may be found.

Bye,
bearophile